The present invention relates generally to the art of fraction collectors, and more specifically to an X-Y fraction collector with minimal moving wires or motors and minimized energy usage.
Fraction collectors are commonly used for collecting liquid fractions originating from a chromatography column or other separation means, where the composition of the liquid varies with time as the liquid emerges from the separation means. Typically, a fraction collector includes a plurality of tubes to receive fractions of the liquid sample, as well as a dispensing means by which the liquid sample fractions are directed into various tubes. The fraction collector is adapted to dispense discrete fractions of the liquid sample into individual tubes so that the fractions, or contents thereof, can be recovered for further use.
Known fraction collectors typically have one of two configurations. So-called “X-Y collectors” utilize a rectangular arrangement of tubes and the dispenser moves in a rectilinear fashion, dispensing fractions into individual tubes. In the second configuration, the tubes are located on a circular turntable, which rotates as the fractions are being dispensed, thereby presenting a separate tube to the dispenser for each desired fraction to be dispensed.
Although both configurations of fraction collector described above are commonly used, each suffers from disadvantages as currently known in the art. While turntable-style fraction collectors are useful, there are instances in which an X-Y collector is preferable. For example, use of an X-Y collector preserves valuable bench space as compared to a turntable collector when a large number of tubes are being filled. Further, commonly used receptacles such as microtitre plates have wells that are generally arranged in a rectangular X-Y pattern. A turntable collector cannot effectively dispense samples into such receptacles.
Disadvantages also exist with respect to X-Y collectors. For example, X-Y collectors generally require the movement of wires as the dispenser moves over a microtitre plate or series of tubes. This movement can lead to breakage of the wires, especially as they lose their elasticity and become more brittle over time. Further, the carriage of such a dispenser generally includes a motor that must be moved along a first axis so that the dispenser can be moved along a second axis once it is properly positioned on the first axis. Movement of portions of the fraction collector having motors located thereon can lead to misalignment of the motor and also increases the load on the motor used to position the carriage, leading to greater energy consumption and an increased likelihood of failure on the part of that motor.
What is needed, therefore, is a fraction collector with fine movement control along its axes, a lack of moving wires or motors, and minimized energy consumption.